001    /**
002     * Licensed to the Apache Software Foundation (ASF) under one
003     * or more contributor license agreements.  See the NOTICE file
004     * distributed with this work for additional information
005     * regarding copyright ownership.  The ASF licenses this file
006     * to you under the Apache License, Version 2.0 (the
007     * "License"); you may not use this file except in compliance
008     * with the License.  You may obtain a copy of the License at
009     *
010     *     http://www.apache.org/licenses/LICENSE-2.0
011     *
012     * Unless required by applicable law or agreed to in writing, software
013     * distributed under the License is distributed on an "AS IS" BASIS,
014     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015     * See the License for the specific language governing permissions and
016     * limitations under the License.
017     */
018    package org.apache.hadoop.hdfs.server.datanode;
019    
020    import org.apache.hadoop.classification.InterfaceAudience;
021    import org.apache.hadoop.classification.InterfaceStability;
022    
023    /**
024     * 
025     * This is the JMX management interface for data node information
026     */
027    @InterfaceAudience.Public
028    @InterfaceStability.Stable
029    public interface DataNodeMXBean {
030      
031      /**
032       * Gets the version of Hadoop.
033       * 
034       * @return the version of Hadoop
035       */
036      public String getVersion();
037      
038      /**
039       * Gets the rpc port.
040       * 
041       * @return the rpc port
042       */
043      public String getRpcPort();
044      
045      /**
046       * Gets the http port.
047       * 
048       * @return the http port
049       */
050      public String getHttpPort();
051      
052      /**
053       * Gets the namenode IP addresses
054       * 
055       * @return the namenode IP addresses that the datanode is talking to
056       */
057      public String getNamenodeAddresses();
058      
059      /**
060       * Gets the information of each volume on the Datanode. Please
061       * see the implementation for the format of returned information.
062       * 
063       * @return the volume info
064       */
065      public String getVolumeInfo();
066      
067      /**
068       * Gets the cluster id.
069       * 
070       * @return the cluster id
071       */
072      public String getClusterId();
073    
074      /**
075       * Returns an estimate of the number of Datanode threads
076       * actively transferring blocks.
077       */
078      public int getXceiverCount();
079    }